1. Field of the Invention
The present invention relates to a method for analyzing a residual fluid retained in an object when performing immersion treatment, and a computer readable medium having a program for permitting a computer to perform an analysis of a residual fluid retained in an object on which an immersion treatment is performed.
2. Description of the Related Art
Electrodeposition coating has widely been used as an undercoating of various members such as a component or a body of a vehicle, since a coating film uniformly adheres to a surface of an object and corrosion resistance is also good. In the electrodeposition coating, by immersing the object in an electrodeposition bath filled with electrodeposition liquid, a coating film is formed on a surface of the object using an electrophoretic phenomenon or an electrodialysis phenomenon, etc. of a polymer electrolyte. The electrodeposition process including the immersion treatment is ended by pulling up the object from the electrodeposition bath.
In electrodeposition coating, it becomes important to perform immersion treatment in consideration of a phenomenon such as a liquid retention or an air retention occurring with the immersion treatment from the standpoint of uniform coating film formation. The liquid retention is a phenomenon in which the electrodeposition liquid is retained in space after pulling up the object from the electrodeposition bath. The air retention is a phenomenon in which air is retained in space such as a gap when immersing the object in the electrodeposition bath.
When the liquid retention occurs, in a subsequent treatment process (for example, a dry process), the retained electrodeposition liquid drips off on a coating film surface and it becomes a cause of occurrence of a defective coating film called the so-called secondary drip. When the defective coating film occurs, a worker must scrape the secondary drip by hand and this leads to disadvantages such as an increase in manufacturing cost or a decrease in working efficiency. Therefore, in the related art, for example as disclosed in JP-A-06-88383, immersion treatment with respect to an object is performed after a shape of the object is properly designed so as to suppress the occurrence of liquid retention.
When the air retention occurs, the electrodeposition liquid does not adhere to some region of the object, and it becomes a cause of occurrence of a uncoated region or a coating irregularity. Therefore, in the related art, for example as disclosed in JP-A-10-45037, immersion treatment with respect to an object is performed after a shape of the object is properly designed so as to suppress the occurrence of air retention.
The presence or absence of the liquid retention and/or the air retention occurring in the object can be determined previously by the analysis method using a free surface. However, in the case when a shape of the object is complicated, for example, in the case of a vehicle body, there is a problem that the analysis takes long time since analysis processing becomes complicated.